(() => {
    // 定义一个接口
    interface IPerson {
        readonly id: number,
        name: string,
        sex?: string,
        sayHello()
    }
    const person: IPerson = {
        id: 1234,
        name: '张三',
        // sex: "男",
        sayHello() {
            console.log("Hello World");
        }
    }
})()